You could try a conv oil and see if that helps, or a different synth, or just get a valve job - might as well if its bothering you, and you can replace the AP1 valves with new AP2 valves while you have the head open.

 

Conv oil being something like castrol 5w30 semi synth?

I think I'll change the oil then do a valve adjustment if it's no better

 

I think some people have complained of synth oil and valve noise, like using Mobil1 and having noise, and changing oils to alleviate the problem. So maybe its an oil thing, and puffs of smoke from idle means some blow by or bad seals, so again, it might be the synth oil making the issue bigger/more noticable.

 

Ok, sorry I'm confused as to what oil to try?
Thanks for your help.